Sheet feed mechanism

ABSTRACT

Sheet feeding means wherein the sheets are fed successively across a feed table into engagement with screw elevating means. The sheets are fed beneath a first pair of screw elevating means which are suspended above the feed table. In one form of the invention, the sheets are fed directly into engagement with a second pair of screw elevating means and the trailing edges of the sheets are lifted by continuously rotating cam means into engagement with the first pair of screw elevating means. In another form of the invention, the sheets are fed beneath the suspended pair of screw elevating means into a stop means which also function to lift the leading edges of the sheet into another pair of screw elevating means. The trailing edge is lifted into engagement with the suspended pair of screw elevating means as in the first embodiment. In each embodiment, after a sheet has been elevated, it is fed out of engagement with the screw elevating means at right angles to its feed into the screw elevating means. The embodiment employing the stop means also incorporates a sheet reject mechanism in which the stop means are pivoted out of the way of an oncoming sheet which has been previously detected to be defective.

United States Patent Lehmann et al.

[ 1 Aug. 1,1972

[54] SHEET FEED MECHANISM [72] inventors: Karl Friedrich Lehmann, Murray Hill, N.J.; Robert Miller Weygant,

Waukegan, Ill.

[73] Assignee: American Can Company, Greenwich, Conn.

[22] Filed: Dec. 21, 1970 21 Appl. No.: 100,092

[52] US. Cl. ..l98/104, 271/51, 271/87 [51] Int. Cl. ..B65g 37/00 [58] Field of Search ....271/87, 51, 80; 198/104, 213, 198/20 R [56] References Cited UNITED STATES PATENTS 1,985,697 12/1934 Stecher ..l98/l04 X 790,157 5/1905 Rose et al ..271/87 UX 3,122,230 2/ 1964 Bogue ..l98/ 104 X Primary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Robert P. Auber, George P. Ziehmer, Leonard R. Kohan and Harries A. Mumma [57] ABSTRACT Sheet feeding means wherein the sheets are fed successively across a feed table into engagement with screw elevating means. The sheets are fed beneath a first pair of screw elevating means which are suspended above the feed table. In one form of the invention, the sheets are fed directly into engagement with a second pair of screw elevating means and the trailing edges of the sheets are lifted by continuously rotating cam means into engagement with the first pair of screw elevating means. In another form of the invention, the sheets are fed beneath the suspended pair of screw elevating means into a stop means which also function to lift the leading edges of the sheet into another pair of screw elevating means. The trailing edge is lifted into engagement with the suspended pair of screw elevating means as in the first embodiment. In each embodiment, after a sheet has been elevated, it is fed out of engagement with the screw elevating means at right angles to its feed into the screw elevating means. The embodiment employing the stop means also incorporates a sheet reject mechanism in which the stop means are pivoted out of the way of an oncoming sheet which has been previously detected to be defective.

8 Claims, 12 Drawing Figures PATENT ED M19 1 I97? SHEET 1 OF 9 ATTORNEY PATENTEDAus 1:912 v sum 3 OF 9 ATTORNEY PATENTEDAUB H912 3.680.679

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- snmsore I\ INVENTORS ma F/Pmp/P/maammw a yzwr A0445? meramvr ATTORNEY SHEET FEED MECHANISM equipment while still maintaining control over the sheets. For example, in the transfer of can body blanks, it is desirable to be able to feed the blanks froma straight line to a rotary path such as is encountered in transferring to a rotary turret. It is also desirable to be able to effect transfer of sheets from one device to another which are traveling at different speeds.

In accordance with the present invention, sheets such as can body blanks, are fed very rapidly in a straight line path across a suitable feeding surface and then elevated out of the plane of infeed by suitably positioned screw elevating means. Thereafter, the sheets are fed out of engagement with the screw elevating means at right angles to the infeed direction.

The invention permits considerably higher conveyor speeds to be employed than has been possible heretofore. It has been found that lighter materials may be used and that efficiency is greatly improved.

In one form of the invention, the sheets are fed beneath a first suspended screw elevating means directly into the bight of a second screw elevating means. A continuously rotating cam means is timed with the sheets being fed such that it will elevate the trailing edge of the sheet in order to lift it into engagement with the suspended screw elevating means. In this manner, the trailing edge of the sheet is lifted out of the path of the next succeeding sheet. After the sheet has been elevated, a cross feed means drives an individual blank out of engagement with the first and second screw elevating means into engagement with cooperating pinch roller means whereby the sheets are delivered at right angles to the infeed direction.

In a second form of the present invention, the sheets are fed beneath a suspended first screw elevating means as in the first embodiment. However, they are then fed directly into a stop means which not only stops the forward advance of an individual sheet but also lifts it into engagement with a second screw elevating means which itself is also suspended above the feed table. As in the first embodiment, a continuously rotating roller means lifts the trailing edge of the sheet into engagement with a suspended first screw elevating means whereby the sheet is lifted vertically out of the path of the next oncoming sheet. Means are again provided for feeding the blanks out of engagement with the first and second screw elevating means into engagement with cooperating pinch rolls. In this embodiment, the stop means may be pivoted out of the way of an oncoming sheet, which has previously been detected to be faulty, thereby providing a reject mechanism.

In both forms of the invention, it is preferred to use a novel helical screw means to drive the blanks out of engagement with the screw elevating means into engagement with the cooperating pinch rolls. The helical screw means imparts an acceleration to the sheet which matches the curvature of the radius of the discharge pinch rolls.

The inherent advantages and improvements of the present invention will become more readily apparent upon considering the following detailed description of the invention and by reference to the drawings in which:

FIG. 1 is a side elevationalview illustrating the sheet infeed means of the present invention;

FIG. 2 is an elevational view in vertical cross section taken along the line 2-2 of FIG. 1;

FIG. 3 is a plan view taken in horizontal cross section along line 3-3 of FIG. 2;

FIG. 4 is a side elevational view taken in vertical cross section along line 4-4 of FIG. 2;

FIG. 5 isa side elevational view illustrating a modified form of the present invention;

FIG. 6 isan end. elevational view, with parts broken away, as viewed along line 6-6 of FIG. 5;

FIG. 7 is a plan view taken in horizontal cross section along line 7-7 of FIG. 5;

FIG. 8 is a fragmentary elevational-view taken in vertical cross section along line 8-8 of FIG. 7 showing one position of a sheet reject mechanism;

FIG. 9 is a fragmentary elevational view similar to FIG. 8 but showing another position of the sheet reject mechanism;

FIG. 10 is a fragmentary elevational view taken in vertical cross section along line 10-10 of FIG. 2;

FIG. 11 is a fragmentary elevational view taken in vertical cross section along line 1-1-1 1 of FIG. 3; and,

FIG. 12 is aschematic diagram of the pneumatic control circuit for the vents shown-in FIGS. 10 and l 1.

While the various features of this invention are hereinafter illustrated and described with respect to the feeding of can body blanks, it is to be understood that the various features of this invention can be utilized singly or in a variety of combinations with sheet feeding means generally.

Therefore, this invention is not limited merely to the embodiments illustrated in the drawings because the drawings are utilized herein merely to illustrate one of a wide variety of uses of this invention.

Referring now to FIGS. 1 and 2 of the drawings, a pair of sheet feed rollers 10 and 12 feed sheets of material, such as can body blanks, in succession across a feed table l4'which provides a can body blank feeding surface. As illustrated in FIG. 2, a guide plate 16 is positioned atop the feeding. surface 14 and provided with an aperture substantially in alignment with an aperture in the feed table 14 to provide a notching and cutting station, indicated generally at 18. This notching and cutting station utilizes cooperation notching and cutting rolls 20, 22 but forms no part of the present.

A main drive gear 24 delivers mechanical drive to a suitable drive means indicated generally at 26 in order to advance the feed rollers 10 and 12. In this manner, can body blanks are fed toward and beneath a first pair of screw elevating means 28 and 30 which are suspended from a main support structure 32.

Reference to FIGS. 1, 2 and 3 illustrates a second or rearmost' pair of screw elevating means 34 and 36. In this embodiment of the invention, the lowermost thread on each of the second pair of elevating screw means 34 and 36 is beneath the level of feed table 14 so that the can body blanks are fed directly into engagement with the second pair of screw elevating means 34 and 36 after passing beneath the first screw pair 28, 30.

FIG. 2 shows one suitable lifting means for the trailing edge of the sheets being fed. Thus, there is shown a cam 38 which is rotated continuously on shaft 40 and which is so positioned with respect to the upper surface of feed table 14 that it engages the trailing edge of a can body blank afier it hasbeen fed beneath the first pair of screw elevating means 28 and 30, and lifting the trailing blank edge into engagement with the second pair of screw elevating means 34 and 36. z

Screws 28, 30, 34 and 36 rotate continuously so as to elevate a can body blank engaged thereby above feed table 14. In the course of its elevation, an individual can body blank is acted upon by a heliconoidal transfer screw 42 so as to drive the can body blank laterally out of engagement with the first and second pairs of screw elevating means and into engagement with cooperating discharge pinch rolls 44 and 46. In this manner, the blank is fed out of engagement with the first and second screw elevating means at right angles to the direction of feed provided by the feedrollers l and 12. It will be appreciated that the linear speed of the can body blank toward the cooperating discharge pinch rolls prior to engagement with the helical transfer screw 42 is initially zero whereby an acceleration is provided by the helical transfer screw 42 which preferably matches the curvature of the radius of the discharge pinch rolls 44 and 46.

When ferrous metal sheets are being fed by the sheet feeding mechanism, it is preferred to use lifter roller segments 48 such as are illustrated in FIG. 3 in place of the continuously rotating cam 38 on shaft 40 of FIG. 2. The roller segments 48 are secured to shaft 40 by means of keys 50 in order to provide eccentric rollers indicated generally at 52. Rollers 52 carry permanent magnets 54 which attract ferrous metal sheets to the continuously rotating eccentric rollers 52 and prevent them'from bouncing in the'course of their feed. Thus it is possible to transfer the trailing edge of the sheets into engagement with the first screw elevating means ,28 and 30 with precision. l

' Reference is now made to FIGS. -7 'whereina modified form of the present invention is illustrated. In this form of the invention, both the forward and the rearward screw elevating means are suspended above the feed table 114, FIG. 7. As in the previous embodi- I FIGS. 5, 8 and 9, the stops 117 each has a substantially V-shaped leading edge 119 which not only serves to stop the advance of a blank 8 shown in FIGS. 8 AND 9, but also functions to elevate the blank slightly whereby the leading edge of the blank may be engaged by the threads on .the suspended lower end of the screw elevating means 134 and 136. As in the previous embodiment, the trailing edge of the body blank B islifted byengagement either with eccentric rollers 152 or by a continuously rotating cam as in the previous embodiment. A helical transfer screw 142 (FIG. 6)-feeds the body blanks out of engagement with the screw elevating means 128, 130, 134, l36'into engagement with cooperating discharge pinch rolls shown in phantom at 144 and 146. I

In this embodiment of the invention, a I reject mechanism is indicated generally at 80 in FIGS. 5 and 7. The reject mechanism is shown to comprise rearwardly projecting arrm 82 and 84 which are clamped to rock shaft 86 by means of bolts 88. Forwardly projecting arms 90, 92 and 94 carry the stops 117 by being bolted thereto by means of bolts 96, FIGS. 8 and 9. The undersurface 98 of the forwardly projecting arms of reject mechanism 80 provide a reject means for the body blanks B by being pivoted or tilted from theFIG. 8 position to the FIG. 9 position in a manner to be described hereinafter.

In order to actuate the reject mechanism 80, a solenoid 100 (FIG. 7) is provided with level arms 102 and 104 interconnected with shaft 86 by having lever 104 clamped thereto by means of bolt 105. Actuation of solenoid 100 causes oscillation of shaft 86 which in turn results in a pivoting action for the reject mechanism 80. This pivoting of the shaft is resisted by a a by being clamped thereto by bolt107. Therefore, as

solenoid 100 is actuated, shaft 86 oscillates or rotates in a limited arc in a counterclockwise direction and v and suitable hand valve controls 196 and 198 regulate nection with the feeding of lightweight sheet blanks such as non-ferrous sheets, typified by aluminum or foil-paper laminates. The feed table 14 is provided with a series of vents and 162 on oneside of the cam 38 and vents and 172 on the other side thereof. In

" each instance a suitable sealing member 164 and 174 respectively is used to provide a seal between the feeding table 14 and a base plate 166 and 176 on the downstream side. Each base plate 166 and 176 is provided with a port such as is shown at 168 and 178,

respectively. Air under vacuum is supplied to ports I68 and 178 which communicate to the vents 160, 162, 170

and 172 in the manner illustrated in FIG. 12. Thus,

there is a coupling to a source of vacuum, indicated generally at 190, connected in series with a valve means such as a needle valve 92. Pressure gauge 194 indicates the amount of vacuum pressure in the line the control of the vacuum to the respective ports 168 and 178 which in turn lead to vents 160, 162, 170 and 172. In this manner it is possible to employ a high velocity air film between the blank and the surface of the feeding table which permits the blank to be held against the continuously rotating cam 38. This action is somewhat like a venturi effect and the air film also provides gas lubrication.

In operation, and referring to FIGS. 1-4, the blanks are fed across surface 14 by means of feed rolls 10, 12

and beneath the first pair of screw elevating means 28 and 30 into engagement with the second screw elevating means 34 and 36. A continuously rotating roller means which is either a cam 38 or eccentric roller 52 elevates the trailing edge of the blank into engagement with the first pair of screw elevating means. In this manner the blank is promptly elevated out of the path of the next oncoming blank which thereby may be fed in at a very high linear speed. Helical transfer screw 42 feeds the blank out of engagement with the first and second pair of screw elevating means into engagement with cooperating discharge pinch rolls 44 and 46.

In the embodiment shown in FIGS. 5-7, the second screw elevating means is suspended above the feed table as well as the first pair of screw elevating means. Stop means 117 function not only to stop the blank but also to impart a slight elevation thereto into the bight between adjacent threads of the second screw elevating means 134 and 136. As in the first embodiment, either a cam or eccentric 'roller means elevates the trailing edge of the blank into engagement with the first pair of screw elevating means 128 and 130. Once again a helical transfer screw member 142 delivers the blank into the nip of cooperating discharge pinch rolls 144 and 146 imparting an acceleration to the blank consistent with the radius of curvature of the pinch rolls.

In this form of the invention, the stop means may be pivoted out of the path of the oncoming body blanks B whereby the blanks engage the under surface 98 of the reject mechanism 80 in order to prevent the elevation of the blank and discharge it into any suitable reject collection means. It is contemplated that any defect may be detected by previously scanning in well known manner the sheets for defects, such as for coating defects, and this information is then relayed to stop solenoid 100 for the rejection of the blank. The reject mechanism 80 functions by pivoting the stops 117 out of the way of the oncoming blank. This motion is effected by actuation of solenoid 100 which through lever arms 102 and 104 is connected to a shaft 86 to which the reject mechanism 80 is also clamped. The oscillation of the shaft 86 is opposed by and returned to its initial position by spring 108 acting on a return lug The blanks may be held against the continuously rotating roller means which, forpurposesz otf this invention, may be either a cam-or aneccentricallymounted roller. The blanks are held thereagainst either by neans of permanent magnets when ferrous metal blanks are being fed or by vacuum jets when non-ferrous metal blanks are being fed. a

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention, the forms hereinbefore described being merely preferred embodiments thereof.

What is claimed is: 1. An apparatus for feeding can body blanks comprising:

a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges,

c. first screw elevating means suspended above said blank feeding surface,

1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank has been fed beneath said first screw elevating means,

d. second screw elevating means engageable with the leading edges of successively fed blanks,

e. means for lifting the trailing edge of each of said blanks into engagement with said first screw elevating means, and

f. means including a heliconoidal feed screw means for feeding said blanks out of engagement with said first and second screw elevating means after said blanks have been elevated out of the plane of said blank feeding surface.

2. An apparatus for feeding can body blanks as defined in claim 1 wherein saidmeans for feeding said blanks out of engagement with said first and second screw elevating means further includes additional feed roller means into which said blanks are fed by said heliconoidal feed screw means.

3. An apparatus for feeding can body blanks as defined in claim 2 wherein said means for feeding said blanks out of engagement with said first and second screw elevating means feeds said blanks at right angles to the direction of feed by said feed roller means.

4. An apparatus for feeding can body blanks comprising:

a. a can body blank feeding surface,

b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges,

c. first screw elevating means suspended above said blank feeding surface,

1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank has been fed beneath said first screw elevating means,

d. second screw elevating means engageable with the leading edges of successively fed blanks,

e. continuously rotating roller means for lifting the trailing edge of each of said blanks into engagement with said first screw elevating means,

. 1. said continuously rotating roller means being magnetized to hold ferrous metal can body blanks against said rotating roller means, and

f. means including a heliconoidal feed screw means for feeding said blanks out of engagement with said first and second screw elevating means after said blanks have been elevated out of the plane of said blank feeding surface.

5. An apparatus for feeding can body blanks comprising:

a. a can body blank feeding surface,

b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges,

c. first screw elevating means suspended above said blank feeding surface,

1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank has been fed beneath said first screw elevating means,

d. second screw elevating means engageable with the leading edges of successively fed blanks,

b. feed roller means for feeding successively across said surface can body blanks having leading and I trailing edges, c. first screw elevating means suspended above said blank feeding surface, 1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank has been fed beneath said first screw elevating means, second screw elevating means engageable with the leading edges of successively fed blanks, e. a cam whose rotational axis lies beneath said blank feeding surface and whose rotation is synchronized with the feeding of said cam body blanks to lift the trailing edges of said blanks into engagement with said first screw elevating means, and f. means for feeding said blanks out of engagemen with said first and second screw elevating means after said blanks have been elevated out of the plane of said blank feeding surface. 7. An apparatus for feeding can body blanks com- P sms:

- blank in order to reject said individual can body blank V 8 a. a can body blank feeding surface,

b. feed roller means for feeding successively across a 1 said surface can body blanks having leading and trailing edges,

c. first screw elevating means suspended above said blank feeding surface, 1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank hasv been fed beneath said first screw elevating means,, l I V (1,. second screw elevating means suspended abov said blank feeding surface,

. e. stopv means for stopping the forward feeding of v said can body blanks and for lifting the leading edges of said can body blanks into engagement with said second screw elevating means,

f. means for lifting the trailing edge of each'of said said first screw blanks into engagement with elevating means,

g. means for moving said stop means out of the path of advance of a can bodyblank as it is feed across i said can body blank'feeding surface in order to prevent said blank from being elevated by said first and second screw elevating means, and

h. means for feeding said blanks out of engagement with said first and second screw elevating means after said blanks have been elevated out of the plane of said blank feeding surface.

8. An apparatus for feeding can body blanks as de ned in claim 7 incl and prevent it from being elevated by said first and You 

1. An apparatus for feeding can body blanks comprising: a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges, c. first screw elevating means suspended above said blank feeding surface,
 1. said first screw elevating means being engageable with said trailing edges of successively fed blanks after each blank has been fed beneath said first screw elevating means, d. second screw elevating means engageable with the leading edges of successively fed blanks, e. means for lifting the trailing edge of each of said blanks into engagement with said first screw elevating means, and f. means including a heliconoidal feed screw means for feeding said blanks out of engagement with said first and second screw elevating means after said blanks have been elevated out of the plane of said blank feeding surface.
 2. An apparatus for feeding can body blanks as defined in claim 1 wherein said means for feeding said blanks out of engagement with said first and second screw elevating means further includes additional feed roller means into which said blanks are fed by said heliconoidal feed screw means.
 3. An apparatus for feeding can body blanks as defined in claim 2 wherein said means for feeding said blanks out of engagement with said first and second screw elevating means feeds said blanks at right angles to the directioN of feed by said feed roller means.
 4. An apparatus for feeding can body blanks comprising: a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges, c. first screw elevating means suspended above said blank feeding surface,
 5. An apparatus for feeding can body blanks comprising: a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges, c. first screw elevating means suspended above said blank feeding surface,
 6. An apparatus for feeding can body blanks comprising: a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges, c. first screw elevating means suspended above said blank feeding surface,
 7. An apparatus for feeding can body blanks comprising: a. a can body blank feeding surface, b. feed roller means for feeding successively across said surface can body blanks having leading and trailing edges, c. first screw elevating means suspended above said blank feeding surface,
 8. An apparatus for feeding can body blanks as defined in claim 7 including reject means carried by said stop means engageable with an individual can body blank in order to reject said individual can body blank and prevent it from being elevated by said first and second screw elevating means. 